Cisco Support Community
Community Member

Supervisor 720-3b reboot loop

We recently wanted to swap our existing WS-SUP720-base with a WS-SUP720-3B in a 6513 chassis.

Had the existing configuration config saved in a txt file and replaced the supervisor. Booting went fine and we pasted in the original config. There was one failure message about unnsupported command but didnt take further notice.

"boot system flash sup-bootflash:" was probaly the line that the 720-3B didnt support.

After wr mem and reload it went in continious loop and rebooting due to inncorrect boot device. Had to put back the old supervisor and have now the 720-3B in a 6504 chassis. Tried some commands in rommon, but are not getting any further. Any suggestions?

Hall of Fame Super Blue

Re: Supervisor 720-3b reboot loop


Where is the image you are trying to load. if it on the actual sup card try

boot system bootdisk:s72033-adventerprisek9_wan-mz.122-18.SXF6.bin

If you are trying to load it off a card do you have a properley formatted pcmcia card in slot0 on your sup ?


Community Member

Re: Supervisor 720-3b reboot loop


Have no pcmcia cards. Its just the ATA(?) bootdisk on the sup. If i try dir bootdisk: i can see the image. Trying the set command indicates that the BOOTLDR value doesnt appear. The BOOT value is: BOOT=bootflash:,1;

This is a wrong value that came with the old config we tried to use.

Tried also this with the result:

rommon 1 > boot system bootdisk:s72033-ipservicesk9_wan-mz.122-18.SXF7.bin

Loading image, please wait ...

Invalid device specified

Booting from default device

device does not contain a valid magic number

boot: cannot open "bootdisk:"

an alternate boot helper program is not specified

(monitor variable "BOOTLDR" is not set)

and unable to determine first file in bootflash

loadprog: error - on file open

boot: cannot load "system bootdisk:s72033-ipservicesk9_wan-mz.122-18.SXF7.bin"

rommon 2 > dir bootdisk:

Initializing ATA monitor library...

Directory of bootdisk:

2 81764868 -rw- s72033-ipservicesk9_wan-mz.122-18.SXF7.bin

rommon 3 >set

PS1=rommon ! >



RET_2_RTS=20:32:37 PST Sun Apr 1 2007







rommon 4 >

Hall of Fame Super Blue

Re: Supervisor 720-3b reboot loop


Apologies. The command

boot system bootdisk:s72033-ipservicesk9_wan-mz.122-18.SXF7.bin

should be put into your config when the system is up and running.

From rommon mode try

boot bootdisk:s72033-ipservicesk9_wan-mz.122-18.SXF7.bin


Community Member

Re: Supervisor 720-3b reboot loop

Have tried boot bootdisk:s72033-ipservicesk9_wan-mz.122-18.SXF7.bin without success. Should there be only one file in the directory?

Community Member

Re: Supervisor 720-3b reboot loop

Try this :


Step 1

rommon 1> set


Note For Supervisor Engine 32, the file name is

Displays the boot variables.

Step 2

rommon 2> BOOT=

rommon 3> CONFIG_FILE=

Clears the boot variables.

Step 3

rommon 4> BOOT=slot0:c6msfc3-psv-mz.121-17d.SXB1.bin

Note slot0: could also be disk0: if you are using an ATA flash disk.

Note For Supervisor Engine 32, the image name is

Sets the boot variable to point to the Cisco IOS image on the PCMCIA card or local.

Step 4

rommon 5> sync

Causes the above changes to take effect.

Step 5

rommon 6> reset



Standby console disabled
Standby console disabled

Resets the supervisor engine from the ROMMON prompt

Cisco Employee

Re: Supervisor 720-3b reboot loop

The issue looks like to me with the empty boot string "BOOT=bootflash:".

Try this

rommon1> BOOT=


rommon3> BOOT=bootdisk:


rommon5> reset

Let us know if that works.


Cisco Employee

Re: Supervisor 720-3b reboot loop

Also, could you please paste the uutput of "dev" from the rommon prompt like,

rommon1> dev

Also can you try reseating the CF adaptor on SUP and check if this helps. See below link :


Community Member

Supervisor 720-3b reboot loop

You have to go into ROMMON and erase the config file for both the switch processor and the route processor. So you'll go into ROMMON twice.

1. Reboot the switch

2. Immediately issue the Control-Break to escape autoboot & enter ROMMON

3. You can clear the config file and boot statements either by the confreg command or by setting the variables as described above



4. Issue the sync command to save to nvram and then reset to reboot

5. Now this time when the switch reboots WAIT TO HIT CONTROL-BREAK UNTIL YOU SEE

          OIR-SP-6-CONSOLE: Changing console ownership to route processor

6. Follow the same ROMMON process as you did under the switch processor and reboot again

7. This time when it reboots it should take you into the Initial System setup

CreatePlease to create content